# US 11,078,219 B2 · Method for producing coordinatively unsaturated metal-organic framework and coordinatively unsaturated metal-organic framework > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,078,219 B2 - Document ID: US11078219B2 - Status: Granted - Kind: B2 - Application number: 16/435,743 - Filed: 2019-06-10 - Published: 2020-01-09 - Granted: 2021-08-03 - Earliest claimed: 2018-07-05 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Yoshio Ohashi - Web page: https://patentgrep.com/patent/US11078219B2 ## CPC - C07F 1/02: Lithium compounds - C07F 7/003: {without C-Metal linkages} - C07F 3/02: Magnesium compounds - C07F 5/003: {without C-Metal linkages} - C07F 5/069: {without C-aluminium linkages} - C07F 7/00: Compounds containing elements of Groups 4 or 14 of the Periodic Table - C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22) ## Abstract [OBJECT] To provide a metal-organic framework having high hygroscopicity under low humidity conditions, and a method for producing such a metal-organic framework. [SOLVING MEANS] A method for producing a coordinatively unsaturated metal-organic framework includes the steps of providing a precursor metal-organic framework comprising a metal cluster and a polycarboxylic acid ion and a monocarboxylic acid ion coordinated to the metal cluster, and allowing the precursor metal-organic framework and a metal salt having a Lewis acidity to coexist in a solvent to desorb at least a part of the monocarboxylic acid ion, which is coordinated to the metal cluster, from the metal cluster, as well as a coordinatively unsaturated metal-organic framework, including an M6O8-x(OH)x-type metal cluster and carboxylic acid ions including a polycarboxylic acid ion as a polydentate ligand and a C1-3 monocarboxylic acid ion as a monodentate ligand coordinated to the metal cluster. ## Claims ### Claim 1 A method for producing a coordinatively unsaturated metal-organic framework, comprising: providing a precursor metal-organic framework comprising a metal cluster, and a polycarboxylic acid ion and a monocarboxylic acid ion which are coordinated to the metal cluster, and allowing the precursor metal-organic framework and a metal halide salt having a Lewis acidity to coexist in a solvent to desorb at least a part of the monocarboxylic acid ion which is coordinated to the metal cluster, from the metal cluster, wherein said coordinatively unsaturated metal-organic framework comprises; an M6O8-x(OH)x metal cluster, and carboxylic acid ions coordinated to the metal cluster, wherein M is a tetravalent group IV element ion or a rare earth ion, wherein the carboxylic acid ions coordinated to the metal cluster comprise a polycarboxylic acid ion as a polydentate ligand and a monocarboxylic acid ion as a monodentate ligand, wherein a plurality of the metal clusters are bonded to each other due to the polycarboxylic acid ion, wherein the amount of monocarboxylic acid ions coordinated to the metal cluster is 80% or less, when the maximum amount of monocarboxylic acid ions which can coordinate with the metal cluster is 100%, and wherein the maximum amount of monocarboxylic acid ions which can coordinate with the metal cluster is six for each metal cluster. ### Claim 2 (depends on 1) The method according to claim 1, wherein the polycarboxylic acid ion and the monocarboxylic acid ion coordinated to the metal cluster are a polycarboxylic acid ion as a polydentate ligand and a C1-3 monocarboxylic acid ion as a monodentate ligand, respectively, and wherein less than six monocarboxylic acid ions are coordinated to each metal cluster. ### Claim 3 (depends on 2) The method according to claim 2, wherein M is at least one selected from the group consisting of Zr4+, Hf4+, and Ce4+. ### Claim 4 (depends on 1) The method according to claim 1, wherein the monocarboxylic acid ion is at least one selected from the group consisting of a formic acid ion, an acetic acid ion, and a propionic acid ion. ### Claim 5 A coordinatively unsaturated metal-organic framework, comprising: an M6O8-x(OH)x metal cluster, and carboxylic acid ions coordinated to the metal cluster, wherein M is a tetravalent group IV element ion or a rare earth ion, wherein the carboxylic acid ions coordinated to the metal cluster comprise a polycarboxylic acid ion as a polydentate ligand and a monocarboxylic acid ion as a monodentate ligand, wherein a plurality of the metal clusters are bonded to each other due to the polycarboxylic acid ion, wherein the amount of monocarboxylic acid ions coordinated to the metal cluster is 80% or less, when the maximum amount of monocarboxylic acid ions which can coordinate with the metal cluster is 100%, and wherein the maximum amount of monocarboxylic acid ions which can coordinate with the metal cluster is six for each metal cluster. ### Claim 6 (depends on 5) The coordinatively unsaturated metal-organic framework according to claim 5, wherein the amount of monocarboxylic acid ions coordinated to the metal cluster is in the range of 5% to 80%. ### Claim 7 (depends on 6) The coordinatively unsaturated metal-organic framework according to claim 6, wherein M is at least one selected from the group consisting of Zr4+, Hf4+, and Ce4+. ### Claim 8 (depends on 5) The coordinatively unsaturated metal-organic framework according to claim 5, wherein the monocarboxylic acid ion is a C1-3 monocarboxylic acid ion. ### Claim 9 (depends on 5) The coordinatively unsaturated metal-organic framework according to claim 5, wherein the monocarboxylic acid ion is at least one selected from the group consisting of a formic acid ion, an acetic acid ion, and a propionic acid ion. ### Claim 10 (depends on 5) The coordinatively unsaturated metal-organic framework according to claim 5, further comprising a out-of-cluster metal ion. ### Claim 11 (depends on 10) The coordinatively unsaturated metal-organic framework according to claim 10, wherein the out-of-cluster metal ion is at least one selected from the group consisting of Li+, Mg2+, Al3+, Sc3+, Y3+, Ti4+, Zr4+, and Hf+.